Material-breaaing apparatus



June 15, 1937. F. H. ARMs'rRoNG 2,083,548

MATERIAL BREAKING APPARATUS Original Filed April 27. 1935 musee PatentedJune 15, 1937 MATERIAL-BRMING APPARATUS Frank H. Armstrongjhicago, Ill.,assigner, by mesne assignments, to Safety Mining Company, Chicago, Ill.,a corporation of Illinois Application April 27, 1935, Serial No. 18,579Renewed July 27, 1936 12 Claims.

This invention relates to material-breaking apparatus, and moreparticularly to improvements in material-breaking shells of the typewherein highly compressed gas is employed as a materialbreaking medium.

. The most satisfactory form of post-charged shell in use prior to thepresent invention employs a chamber, in which a charge oi' highlycompressed gas is stored, and control means for lo the retaining andventing of the charge, which includes a charge release valve means anddifferential-piston controlling means for the latter providing an areaupon which pressure acts to close and hold closed the charge releasevalve ,5 means, and a smaller area subjected to storage chamber pressureand operative when the pressure acting on the larger area is released toopen the charge release valve means and hold it open notwithstanding thesudden and very great reduction in storage chamber pressure which immediately ensues. This smaller area has a communication with the storagechamber controlled by means which permits ready passage of chamberpressure to the arca, but precludes reverse ilow, and thereby prevents asudden drop in chamber pressure 'from also lowering the pressure on thesmaller area and thereby permitting the less rapidly dropping pressureon the larger area. momentarily reclosing the charge release valvemeans, with a resultant charge release in steps. The use of thisessentially one-way connection between this smaller area and the storagechamber, however, results at times in delaying recharging until thepressure acting on the smaller area leaks away, and this dimculty mypresent invention avoids.

An` object of my invention is to provide improved air-breaking apparatusnot subject to the diiilculty mentioned. Another object of thisinverition is to provide an improved materialbreaking shell of the highpressure gas type wherein highly compressed gas is employed as amaterial-breaking medium. A further object is to provide an improvedcontrol means for such ashell for effecting release of thematerialbreaking charge from the shell. A still further object is toprovide an improved differential valve release means for the charge ofmaterial-breaking pressure and having associated therewith improvedcontrol means for said release means. Still another object is to providean improved vent means for the control chamber of the differentialrelease means whereby when the control piston moves into its valvereleasing position the side of the control piston which remains underpressure is automatically connected to exhaust. These and other objectswill hereinafter more fully appear in the course of the followingdescription and as more particularly pointed out in the appended claims.

In the accompanying drawing there is shown for purposes of illustrationone form which the invention may assume in practice.

In this drawing,-

Fig. 1 is a view in longitudinal section of the 10 illustrativeembodiment of the improved material-breaking shell.

Fig. 2 is a view similar to Fig. 1, showing the control piston and valveassembly in released position. 15

In the drawing, A represents a materialbreaking shell-which is in manyrespects of the same general character as that disclosed in my copendingapplication, Serial No. 718,175, filed March 30, 1934, and which is ofthe high pressure gas type wherein a highly compressed gas is employedas a material-breaking medium. 'I'his shell comprises a tubular casing Ihaving a chamber 2 for receiving a charge of high pressure gas, as forexample highly compressed air; 25 and threaded within the inner end ofthis casing is a discharge cap 3 having an axial discharge orifice 4communicable with the pressure chamber 2 and connected by a series ofgenerally radial, outwardly inclined discharge ports 30 5 with the shellexterior. Threadedly secured withinv the outer end of the casing I is acontrol cap 6 having a control chamber l containing a reciprocablecontrol piston 8. The piston rod 9 of this piston extends inwardlywithin the pres- 35 sure chamber 2 and has xed to its inner extremity apressure release valve I Il adapted to seat at II on the inner end ofthe discharge cap to prevent communication of the discharge oriiice 4with the pressure chamber. Positioned be- 40 tween the inner end of thecontrol cap 6 and an internal annular shoulder I2 formed within thecasing I is a heavy steel plate or disc I3 to which is secured a hatleather I4, surrounding and adapted to seal on the exterior surface ofthe 45 valve rod 9, which passes therethrough. The piston 8 consists ofa steel plunger I5 carrying a cup leather I6 held in position by akeeper I 'I threaded on the valve rod 9. Threaded at I8 within thecontrol cap 6 is a conduit I9 adapted 50 to communicate with a suitablesource of high pressure gas or to be vented; and this conduit isconnected through an axial passage 20 with the control chamber 1 at theouter side of the control piston. A suitable check valve 2| with 55 theshell, but preventing flow in the reverse direction. A restricted'radialpassage 25 in the,

rod 8 extends from the axial passage 23 to the exterior ofthe valve rod,and is located at such a point that its'outer end, when the piston andvalve assembly is rin the position shown in Fig. 1, communicates withthe main chamber 2, and

when -the piston and valve assembly is in or close to the position shownin Fig. 2 communicates with the space between the inner side" of thecontrol piston and the disc I3, thereby connecting this space with thechamber 2, and so to atmosphere, noting that the valve I0 is then open.

' The introduction of high pressure gas through the conduit I9 and axialpassage 20 into the control chamber 1 at the outer side of the control'piston results-in axial movement of the valve and plunger assembly tobring the valve I0 into rmsealing engagement with its seat II on the endof the discharge cap 3. At the same time the high pressure gas flowsfrom the control chamber 1 past the check valve 2i, and through passages23, 24 into the main pressure chamber 2. It is important to note that asthe pressure builds lup in the main storage chamber 2, high pressure gaswill pass from said main chamber along the valve rod 9 into the space atthe inner side of the control piston and between said control piston andthe metal plate I3, the hat leather I4 functioning as a check valveopening towards such space under these circumstances. In other words,gas under pressure from chamber 2 passes between the hat leather I4 andthe valve rod 9 and into the space between the inner side of the controlpiston and the disc I3. It will be observed, however, that rapid reverseow along the outside of the rod can not occur when the pressure in themain pressure chamber 2 falls, because of the check valve action of thehat leather which then takes place.

When a charge of high pressure gas of desired value has been introducedinto the pressure chamber 2, discharge thereof is effected by cuttingoff the supply of high pressure gas to the conduit I9 and connecting thelatter to atmosphere. Any suitable means, whether a three lway valve, ormore complex mechanism, may be used for this purpose. This ventingresults immediately in the lowering of the pressure in the controlchamber 'I at the outer side of the control piston, and bearing in mindthat the pressure of the gas trapped in the space at the inner side ofthe control piston between the latter and the disc I3, is substantiallythe same as that of the charge of pressure that was introduced into themain chamber 2, it will be apparent that the reduction of pressure'inchamber 'I at the outer side of the control piston immediately resultsin axial movement of the valve and plunger assembly toward the left fromthe position shown in Fig. 1 to the position shown in Fig. 2 and inopening of valve I 0. Note, of course, that the effective area of valveIll within chamber 2 is less than the effective area of the right handside of piston 8. The initial opening of the control valve I I)naturally results in an immediate and extremely rapid drop in pressureWithin the chamber 2, but in View of the very small size aosasse of thepassage 25, and the check valve action of the hat leather I4, thepressure trapped between the disc I3 and the inner side of the control'piston will be sumciently maintained to preclude the pressure in chamberI outside the piston 8 from reclosing valve I I). Thusythe gas in thespace at the inner side of the control piston serves to move the valveand plunger assembly positively toward open position and to maintain itin that position until the charge has been effectually released. Whenthe passage 25 is in the position shown in Fig. 2 with the control valveI0 in its wide open position, the pressure in the space at the innerside of the control piston vents to atmosphere through the chargechamber, discharge orifice 4, and discharge ports 5, but the size ofpassage 25, and the fact that it comes into communication with the spaceto the left of the hat leather only as valve I Il reaches substantiallyfull open position, maintain the pressure in that space long enough topreclude popping, i. e. serial discharges, due to momentary reclosingsof valve I0. By the time the operator recovers the shell and is ready torecharge it, the pressure in the space mentioned will be vented so fullythat the rst readmission of pressure to chamber 1 through passage 20will readily cause closure of valve III in readiness for a new charge.

It will be obvious that I have provided an improved shell, fullyeffective to prevent popping, and to insure full and free discharge tothe point of its application of the charge of high pressure gas, but yetin readiness as soon as it can again be placed in a hole for recharging.If desired, the valve II) may indeed be reclosed before positioning theshell in a new hole, by joining the shell when held with the dischargecap down.

While I have in this application specically described one form which myinvention may assume in practice, it will be understood that this formof the same is shown for purposes of illustration, and that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a material-breaking apparatus, a material-breaking shell having achamber for receiving a charge of material-breaking pressure. dischargemeans for said chamber, a valve for controlling said discharge means, adifferential piston for actuating said valve and for holding said valveclosed, means for conducting pressure to said shell to act on the largerpressure area of said piston to hold said valve closed, valve meanscarried within the piston for conducting pressure past said piston tothe pressure chamber to act on the opposed reduced area of said piston,said valve means closing automatically upon reverse in flow of thepressure, means for venting the larger area of the piston so that thepressure in the shell acting on the reduced piston area effects openingof the control valve, and means operative when said control valve is inits open position for venting the opposed reduced area of said piston toatmosphere.

2. In a material-breaking apparatus, a shell having a chamber forreceiving a charge of material-breaking pressure, a discharge oriilcetherefor, a valve for closing said orifice, a differential piston forcontrolling said valve, means for introducing pressure into said shell,the pressure acting on the larger pressure area of the Vcompressed gasinto said shell through said sup-w piston to maintain said valve closed,the pressure flowing past the piston to the shell at the other side ofthe piston, means for venting the shell to reduce the pressure acting onthe larger area of the piston so that the pressure in the shell actingon the reduced piston area effects movement of the piston to open saidvalve, and means operative when said valve is in its open position forventing the reduced piston area to atmosphere.

3. A material-breaking apparatus comprising a source of compressed gas,a supply pipe extending therefrom, a material-breaking shell connectedto said supply pipe, said shell embodying a differential valvecontrolling the release of compressed gas from said shell, said valvebeing actuated into closing position by the introduction of ply pipe andbeing actuated to open position when the ilow of gas is reversed, meansfor cutting oif the flow of gas from said source and reversing the flowof gas in said supply pipe, thereby effecting opening of said valve torelease the compressed gas from said shell, and means operative whensaid valve is in open position for venting the gas acting to open saidvalve to atmosphere.

4. A material-breaking shell having a chargereceiving chamber with adischarge orifice and a control chamber, a valve in operative relationto said orifice for controlling the latter, means associated with saidvalve and positioned in said control chamber and responsive to therelative pressures in said charge-receiving chamber and control chamberfor determining the position of said valve, and vent means operativewhen said valve is in open position for venting one end of said controlchamber to atmosphere.

5. A material-breaking shell having a chamber adapted to receive acharge of highly compressed gas and a discharge opening through whichsaid charge may escape, a differential valve within said chamber forcontrolling said discharge opening, means for establishing diiferentialpressures calculated to open said valve, and means operative when saidvalvenis in open position for venting the pressure acting to open saidvalve to atmosphere.

6. A material-breaking shell comprising a charge storage chamber, valvecontrolled means for releasing a charge from said chamber, and valvecontrolling means including means providing an area effective whensubjected to pressure equal to or above charge pressure to maintain thechargev releasing valve means closed, means providing an area effectivewhen subjected to a pressure substantially'equal to charge pressure andwhen said first mentioned area is vented. to eilect opening andmaintaining open of the charge releasing valve means, means for ventingsaid first mentioned area, and means automatically effective upon chargerelease to` lprovide a-retarded venting of saidvsecond mentioned area.

7. A material-breaking shell comprising a charge storage chamber, valvecontrolled means for 'releasing a charge from said chamber, and

valve controlling means including means providing an area eiective whensubjected to pressure equal to or above charge pressure to maintain thecharge releasing valve means closed, means providing an area havingnormally only a one-way communication with the charge storage chamberand effective when subjected to a pressure substantially equal to chargepressure and when said first mentioned area is vented, to effect openingand maintaining open oi' the charge releasing valve means, means forventing said rst mentioned area, and means automatically effective uponcharge release to provide a retarded venting of said second mentionedarea.

8. A material breaking shell having a chamber adapted to receive acharge of highly compressed gas and a discharge opening through whichsaid charge may escapea valve/for controlling said fr Y fr dischargeopening, means operative to open and hold open said valve, and meansrendered operative by the opening movement of said valve `for destroyingthe valve holding action oi' the rstmentioned means.

9. A material breaking shell having a chamber adapted to receive acharge ot highly compressed gas and a discharge opening through whichsaid charge may escape, charge releasing means for controlling saiddischarge opening, means operative to actuate said releasing means toeiect release of said charge and to maintain said releasing means insuch condition, and means rendered operative by the actuation of saidreleasing means for slowly destroying the said maintaining action of thesecond-mentioned means.

10. A material breaking shell having a chamber adapted to receive acharge of highly compressed gas and a discharge opening through whichsaid charge may escape, a valve for controlling said discharge opening,fluid operated means operative to open and hold open said valve, andmeans rendered operative by the full opening movement of said valve forventing the fluid employed for operating said fluid operated means.

1l. A material breaking shell having a chamber adapted to receive acharge of highly compressed gas and a discharge opening through whichsaid charge may escape, a valve for controlling said discharge opening,differential pressure operated means for opening and holding open saidvalve, and means rendered `operative by the full opening movement ofsaid valve for destroying the difierential pressure condition whichoperates to hold the valve open.

12. A material breaking shell comprising a container adapted to receivea high pressure charge and having a discharge orifice adjacent one endthereof, valve means for closing said orifice, releasable means adjacentthe other end of said container for holding the valve means in saidorice, means to effect release of said releasable means, means operativeto open and FRANK H. ARMSTRONG.

